To the present time, the accurate sensing of temperature of a fluid resulting from the mixing of fluids of different temperatures has proved difficult and false temperature values can easily be obtained due to the incomplete mixing of the fluids and/or the positioning of the temperature sensor. For valve systems and the like that rely on accurate temperature sensing as a control signal, inaccuracies in temperature measurement may be particularly problematic. Similar problems may result with mixing of any fluids having different properties, where those properties need to be measured in the mixed fluid.
The term “fluid” is used throughout this specification to cover both liquids and gases. However, by way of simplicity, the present invention will be described particularly in respect of its use in the temperature sensing in conjunction with a mixing valve used for the mixing of hot and cold liquids.
In a domestic or industrial water supply, where hot and cold water is being mixed, a particular problem can be experienced where the hot and cold water pressures and variable hot and cold inlet orifices are substantially equal. This circumstance seems to promote a particular difficulty in correctly ascertaining the temperature of the mixed water, which will ultimately be supplied to the end user.